Valve mechanism for internal-combustion engines



y 1929- E. A. SPERRY VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINESFiled July 21 1919 4 Sheets-Sheet "IIHIIHII Hill,

LV I ENTOR Z'ZERfi/ ERRY E. A. SPERRY VALVE MECHANISM FOR INTERNALCOMBUSTION ENGINES 4 Sheets-Sheet 2 May 7, 1929.

Filed July 21, I919 II/IIIIIIIIIIIIIIIIIIIIII mi" I I g;

6/ a: IIIIIIIIIIIIIIIIIIIII 6 lll/lll ERR Y May 7, 1929. E. A. SPERRY1,711,703

VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed July 21, 1919 4Sheets-Sheet 4 INVENTOR Patented May 7, 1929.

UNITED STATES PATENT OFFICE.

ELMER A. SPERBY, OF BROOKLYN, NEW YORK, ASSIGNOR '10 SPERBY DEVELOPMENTCOIMLPANY, 0F DOVER GREEN, DELAWARE, A CORPORATION OF DELAWARE.

VALVE MECHANISM FOR INTERNAL-COMBUSTION ENGINES.

Application filed July 21,

This invention relates to new and inrproved multiple expansion internalcombustion engines. While the broad principles of construction, asoutlined herein, are applicable to many typcs'of internal combustionengines, the Invention has perhaps its greatest application in compoundengines of the Diesel or constant pressure type enabling a much lighterand cheaper englne construction giving two to three times the horsepowerper pound of the present Diesel engine.

One of the objects of the invention relates to the transfer valve whichcontrols the communication between the high and low pressure cylindersand which deals with unusually hot gases (on the order of 2,000 F. max.)It is important not only that a suitably low heat balance be maintainedwithin the valve, but that the velocity of these hot gases rushing overthe valve seat be kept sufficiently low to prevent erosion. The firstof-these features is accomplished by intensive cooling of the transfervalve, while the second is accomplished by cushioning the flow of thetransfer gases. It will, of course,

be understood that these principles of handling high temperature andcompressed gases are not limited in application to compound combustionengines but have application to other types of heat engines and cycleswherein valves are employed to control the entrance of the hot workinggases. In compound combustion engines a high pressure or combustioncylinder acts, of course, in two capacities, first, as a combustionspace or chamber wherein the fuel is burned to produce the pressure, andsecond, as a means for partially expanding the working gases. The lowpressure or expansion cylinder, on the other hand, operates solely as anexpanding cylinder, the problem of admitting the. hot gases theretobeing substantially the same as in any heat engine wherein combustion-takes place prior to the entry into the cylinder.

A further object is so to arrange the engine that the full benefitofcushioning is had in the low pressure cylinderr While carrying theclearances at as low a point as practicable these clearances are filledwith trapped gases and brought to a pressure equal or thereabouts to thetransfer pressure be- 1919. Serial No. 312,193.

fore or at the time the transfer valve is opened. It is not onlyadvisable that these trapped gases should be brought to this pressure,but also that the gases so utilized should be hot, in order that whenthe transfer valve opens, the hot gases from the high pressure cylinderwill not lose temperature to cooler gases and wire drawing will beavoided. The lnvention also includes the grouping 111 a line of onecentral low pressure cylinder and two high pressure cylinders, or atleast cylinder heads, in one unitary structure preferably provided withthe high pressure clearances in the form of compact domes of assymmetrical a form as possible. Said head structure is preferablyprovided with downwardly projecting skirts forming a part at least ofthe cylinders proper with continuous water jackets surrounding all thehigh temperature regions, the jacketless points being well away from thehighest temperature portions. This unitary head with its pendantcylinders is supported on columns from a bed plate and the lower partsof the cylinders may be braced or guided by the said columns.

A further object of the invention is to employ the most advantageoussize and shape of clearance space for the cylinders to accomplish whichI so design the high and low pressure cylinder ratios as to yield asubstantially hemispherical clearance space in the former.

Other objects will appear in the following description of the invention.

Referring to the drawings wherein I have shown what I now consider thepreferred forms of my invention:

Fig. 1 is a sectional side elevation of an engine constructed inaccordance with my invention.

Fig. 2 is a sectional detail of the combination air-inlet and transfervalve and associated parts.

Fig. 3 is an elevation of one of the members of the said valve.

Fig. 4 is a view of the actuating mechanism of one of the saidcombination valves taken on line 44 in Fig. 1.

Fig. 5 is a sectional side elevation of one of the fuel injectionvalves.

Fig. 5 is a detail thereof.

Fig. 6 is a sectional view showing a modisure piston at 3.

type of valve, in which the fuel injection.

valve is combined with the air-inlet and transfer valves. Fig. 7 is asectional view of the fuel injec tion valve used in this combination.

Figs. 8, 9, and 10are enlarged detalls of parts of this injection valve.

Fig. 11 is an enlarged sectional, detail of a portion of the deviceshown in Fig. 6.

Fig. 12 is avsection taken on line ,12-12,

Fig. 13 is a fra mentary sectional detail.

pressure cylinder; the high pressure pistons eing shown at 1 and 2 andthe low pres- H Passages 1 and 2 are provided for communication betweeneach of the high pressure cylinders and the low pressure cylinder,valves 1" and 2 being provided to close said passages. Said valves arecontained within a structure 4, which also in cludes the air-inlet valvehereinafter described. The fuel inlet valves are shown at 5, and aheatin or igniting grid or bafile 6 may be positione in the path of theinjected fuel within each of the high pressure cylinders.

In order to produce a sufiicient amount of.

combustible material to actuate the low pressure cylinder after thecompletion of the workin stroke of the high pressure piston, I have sown a large clearance space 7 within each of the high pressurecylinders. This space will permit of the compression of a greater amountof air within said cylinders at each compression stroke. This in turnwill permit of the injection of a greater quantity of fuel, whichpreferably will continue throughout a considerable portion of theworking stroke of the high pressure piston, at a rate which will keepthe pressure within the cylinder substantially constant during theperiod of injection.

In order to obtain a high degree of efiiciency in the distribution andcombustion of the incoming fuel, I prefer to constructthe clear- I ance7 hemispherical or dome shaped. This shape, it will'be recognized, willpresent a the ratio of the displacement of the hi h and low pressurepistons be a predetermine value which I have found to be in theneighborhood of one to six or more.

Preferably the fuel injection valve 5-is positioned at or near the topof the dome and substantially coaxial with the lon itudinal axis of theiston within the cylinder, or at least in suc stream of injected fuel issubstantially coincident with said axis of the piston. This will insurea more rapid and equal distribution of fuel within the clearance space 7and effect a more perfect combustion.

The details of one form of fuel injection valve 5 are shown in Fig. 5.This valve is of the solid fuel injection type i. e. the oil itself isplaced under extremel high pressure and is forced into the cylin erwithout the use of compressed air as is commonly done. The

manner thatthe axis. of the fuel is forced in through a small inletvalve 10 and down through channel 11 into recess 12; thence down throughchannels 13 into diagonally disposed channels 14 in member 15- (see alsoFig. 5) whence it enters recess 16 in a whirling motion. It then risesup through channels 17, 18 around the valve stem, the swirling oil isprojected into the cylinder at such a high velocity as to become highlyatomized. The fuel then becomes ignited by the heat of the. compressedgases within the cylinder as well as by contact with the electricallyheated battle 6. Both the time of opening of the fuel valve with respectto the cycle of the engine and the length of time during which itremains open are adapted to be varied. For this purpose I have shownshaft 23 as rocked by means of a lever .26 (Fi s. 15'and 16) pivoted at27 and having a re ler 28 engaging a cam 29 on a sleeve 30 rotatablewith the engine cam shaft 31. Said cam 29 is preferably in the form of atriangle as indicated by dotted lines in Fig. 16, with the advance ed e32 parallel to the axis of the shaft. Spline to the cam shaft 31 is asleeve 33 movable longitudinally thereon by means of a handle 34 pivotedat 35 and provided with a fork 36 engaging between flan es 37 on thesleeve. The sleeve 30 is mounte upon the sleeve 33 and is movablysecured thereto as by means of a pin 38 on sleeve 33 projecting into aninclined 'slot 39 in sleeve 30. Sleeve 30 may be moved upon sleeve 33 bymeans of a handle 34' pivoted at 35' and engagin between collars 37 onsaid sleeve 30. It will be readily apparent that as sleeve 30 is movedlongitudinally, it will also be rotated with respect to shaft 31, but ifsleeve 33 is so moved with sleeve 30 no rotation of either sleeve willtake place. If it is desired to vary the length of time during which thefuel valve is to remain open, sleeve 33 will be actuated with sleeve 30.This will move cam 29 laterally with respect to roller 28 so that saidroller will have to pass over the cam at a point where the width of thelatter is greater 01' less. The roller will thus be lifted at the sametime with respectto the cycle of the engine, but will remain lifted fora longer time. By actuating only sleeve 30 cam 29 will besimultaneously' rotated and moved laterally, so that the time of openingof the valve as well as the length of time that it remains open will bevaried. To vary the time of opening, sleeve 33 alone will be actuated,handle 34' being held still. This will cause sleeve 30 to rotate, due tothe pin and slot connection, without moving longitudinally wit-l1respect to shaft 31. By proper mani ulation of both handles 34 and 34'it is evi ent that any desired time of opening of the fuel valx e aswell as the length of time during which it is held open may be effected.

The preferred details of the combination transfer and air-inlet valve 4,which is shown positioned to one side of the fuel valve 5, are shown inFig. 2. The transfer valve 1 is shown as comprising a hollow orsleeve-like member, flaring outwardly at its lower extremity and seatingagainst the wall 39 of the valve casing at 40. Said sleeve is alsoprovided with two flanges 40, 41 bearing against walls 39. The air-inletvalve42 is shown within the sleeve-like transfer valve l and may beprovided with spiral ribs 43 (see also Fig. 3) resting against theinside of the transfer valve at 44 and acting as a guide as well ascooling ribs for the inlet valve. Said valve is also provided with apiston 45 hearing against the walls of the transfer valve at 46. Theinlet valve is shown as seating against the flaring walls of thetransfer valve at 47, thus closing the interior of the sleeve from thehigh pressure cylinder.

The charging air which is supplied to the cylinder from a tank 48(Fig. 1) is led in through pipe 49, and enters the valve at 50. flowingthrough ports 51 to the interior of the transfer valve and rushes intothe cylinder 1 when the inlet valve 42 is opened. The valves are heldnormally closed by the pressure of the compressed air by reason that theair circulated through the valves will exert an upward and a downwardpressure against flange 40 on the transfer valve; a downward pressureagainst flange 41 and an upward pressure against the flaring portion 52.The areas of these surfaces are so proportioned that the combined upwardpressures will overcome the combined downward pressures, thus holdingthe valve upwardly against its seat. The upward pressure against flange45 will also overcome the downward pressure against the flaring portion53, so that the inlet valve 42 will also be held closed.

For actuating the valves, a pair of lovers 54, 54' are provided. Lever54 is rigidly mounted on a shaft 56 having its bearing in a bracket 57.On the opposite end of said shaft is provided a PI'OJGCtlOIl 58 (seealso Fig. 4) engaged by a lever 59: Said lever is pivoted at and carriesa roller 61 engaging a cam 62 on cam shaft 31. The actuation of saidlever by said cam effects the tripping of projection 58 and arm 54 todepress and open valve 42. The transfer valve 53 is pro= vided at itsupper end with a circumferential groove 63, within which the ends 64 ofa bifurcated arm 54 engage. Said arm is secured to shaft 56' providedwith a projection 58 engaged by a lever 59 also pivoted at 60 andprovided with a roller 61 actuated by a cam 62 on shaft-31. Theoperation in the same as in the case of valve 42. Preferably theintake-transfer valve is eccentrically placed in a horizontal plane withrespect to the high pressure cylinder as indicated in Fig. 13 so thatthe incoming air will be given a vortex or swirling motion as indicatedby the arrows 67 in said figure about the circular walls of thecylinder, thereby securing a uniform combustible mixture.

The cooling of the valves will be eflected by contact with the aircirculated therein and especially by the wash of compressed air rushinginto the cylinder. In order to distribute the heat from the lower partof valve 42 throughout the stem 57 thereof and ribs 43, the inside ofsaid valve and stem may be made hollow as shown and a small quantity ofmercury or other volatile liquid 64 provided therein. The mercury byevaporation and condensation will cause rapid distribution of heat alongthe valve stem where it will be absorbed by the incoming air.

After the combustion of the mixture in the high pressure cylinder andthe completion of the working stroke of the piston therein, (the lowpressure piston 3 being then in the upper position as shown in Fig. 1)the transfer valve 1 is designed to open and permit the gases to flowinto the low pressure cylinder to force the low pressure piston down onits working stroke. At the end of this stroke the transfer valve willclose and the exhaust valve 65 in the low pressure cylinder will open,permitting the gases to flow out through openings 66 and escape. In themean time the opposite high pressure cylinder, as for instance cylinder2, will have been repeating the functions of cylinder 1 so as to beready to discharge its partially expanded gases into the low pressurecylinder as soon as piston 3 reaches its upper position again.

When at the end of the up stroke of the low pressure piston and the downstroke of the igh pressure piston the transfer valve opens and permitsthe partially expanded gases to ass mto the low pressurecylinder,ordinari- Fy there would be a sudden rush of the highly compressed andheated gases throughpassages 1 or 2 into said low pressure cylinder. Thepressure in the high pressure cylinders rises to 400 pounds or more persquare inch. The

shock of this sudden inrush would tend to produce jerky action on thepart of the engine, while the intensely high velocities at the instantof opening would cause pitting and erosion of the valve seats. Moreover,too sudden expansion of the gases would be attended by a correspondingloss of energy. '10 overcome these objections compressed air or othergases may be supplied to the clearance space 3 in the top of the lowpressure cylinder and passages 1*, 2, substantiall equal to the pressureof the gases in the hig pressure cylinder at the moment of o ning of thetransfer valve. In addition, there are more or less remote chambers suchas annular chambers 52' within the valves which must be filled with asthrough said passages 1 and 2 and broug t up'to transfer pressure at thetime of opening the transfer valve, as well as the main clearance space.Such passages and remote chambers naturally require more time to fillthan the main clearance space and hence in order to fill the same it isessential that the rise in pressure he radual. Also, of course, suchpassages and c ambers serve to increase the volume of the clearancespace to be filled at the time the transfer valve is opened, so that, ifthe pressure in said space is materially less than the pressure in thecombustion cylinder, a large volume of white hot gas rushes over thetransfer valve to fill it. Preferably this compressed gas is supplied byclosing the exhaust valve 65' of the low pressure cylinder before theend of the exhaust stroke of the piston, so that the gas then remainingin the cylinder will-be compressed by the remainder of the up stroke.Upon the opening of valve 1 then the transfer of gases will take place.smoothly. It is also preferred that the temperature of this compressedor cushioning gas in the low ressure cylinder should be of substantiallyt esame temperature as the transfer gases. In this connection it will berecognized that while the gas loses a great deal of heat in work, itwill still possess considerable heat at the completion of its work, sothat when a portion of-it is again highl comressed the heat reacquiredalong with the heat retained will be considerable.

At this point attention is called to the full andunique significance ofcushioning as it is applied to this invention in its relation to theeculiar and novel cycle operation disclosed .lierein. The facts are thatthe transfer valve is required to handle gases at temperatures andpressures heretofore thought im ossible and never before successfullyaccomplished in the art. Nor-has a valve in any hi h pressure combustionengine ever been cal ed upon to handle the ver large volume of gasespresent in this eye e in which my high pressure chamber may handle fromsix to seven times the volume of gases handled by the Diesel engine ofsimilar dis lacement. To illustrate what I am enable to,accomplish bythe correct application of cushioning under these critical. conditionslet-us for the moment consider that the ordinary exhaust valve of anexplosion or Otto cycle engine were opened at the highest pressures andtemperatures reached after ignition where the temperatures are probablyabove the melting point of platinum and the pressures are on an equalitywith the transfer pressure in my cycle. Upon the first breaking awayofthe valve from its seat the white hot gases start and rush over thesedelicate fitting surfaces with an enormous velocityabout 4 miles persecond. This, together with the terrific heat present, causes seriouserosion of these surfaces and they are almost instantly riddled with deefurrows and the surfaces of both valve an seat are literally washed awayand disappear exactly as do the inner surfaces of the nozzle of heavyordnance, and from the same cause, namely the high velocity escape ofthe hot gases as the rear end of the locking ring and shell emergesfrom'the gun. How long would this gun nozzle last if we fired. attherate of several rounds per second as is the case with my transfer valveI have succeeded in meetingthis almost impossible situation, haveovercome the difliculty, and have been able to secure practicaloperation of these valves, so vital to successful performance bycompelling the low pressure cylinder in the latter part of its exhauststroke to act as a high pressure compressor. By selecting a criticalpoint for closing the exhaust valve the piston is caused to trap and compress the hot products of combustion to the exact pressure of the gasesin the high pressure cylinder at the instant of opening the transfervalve. Under these conditions no flow whatever takes place upon thebreaking away of the valve from its seat and not until the valve isalmost completely 0 en and then the gases slowly start to flowon y asthe piston slowly starts on its outward stroke. The flow is underperfect control and is limited in velocity which is actually much lessthan the outward speed of the piston owing to the extremely large lowpressure volume and the correspondingly large proportion of the totalexpansion of the gases, all of which takes place after they have passedthe transfer valve and entered the cylinder;

A complete cycle of operation of the engine, therefore, is as follows:On the down stroke of high pressure piston 1' air isdrawn into thecylinder through the air induction valve. On the up stroke of piston 1the air is compressed to a high degree of compression sufiicient to heatthe air so as to cause ignition when mixed with fuel. Near the end ofthe upper stroke of piston 1, fuel is injected through the fuelinjection valve and the mixture ignited. A wer stroke is now obtained onthe down, stro e of piston 1. On the return upward stroke of said pistonthe transfer valve between the high and low pressure pistons opens andthe upward movement of piston 1' causes discharge of the mixture intothe low pressure cylinder. The high and low pressure pistons being 180out of phase, the expanding mixture entering the low pressure cylinderas piston 1' rises causes the descent of the low pressure piston. Onthis power stroke of the low pressure piston air is compressed by thepump 104 to supply compressed air to the air reservoir. Since thepistons 1' and 2' are 360 out of phase, the low pressure piston willreceive a power stroke on each of its downward movements because eachfourth stroke of pistons l and 2 is effective and these strokes are 360out of phase.

Referring now more specifically to the fuel igniting means 6 in the highpressure cylinders, the coil may be somewhat umbrellashaped so that theincoming oil s ray represented by dotted lines 68 may be t erebydistributed equally throughout the cylinder and be more completelyvaporized as well as ignited. Current is led into and away from the coilby means of wires 69, 70 secured in a plug 71. For supplying the currentI have shown in Fig. 14 a' motor generator 2,"comprising a motor 73 anda low voltage high current generator 7 4 having a separately excitedfield, the terminals of which are indicated at 7 5, 76. The motor andthe fields of the generator are excited from line wires 77, 7 7, wire 77being connected to the generator through a rheostat 78, while currentfrom the armature of the generator is carried directly to the heatingcoils 6, 6; one side of the armature and one side of each coil beinggrounded. The strength of the generator fields is automaticallycontrolled so that the current supplied to the heating coils may begoverned in accordance with the requirements of the engine. Handle 79represents the control handle of the engine for starting and operatingthe same. The full line position is the start ing position and thedotted line position the running position. On the shaft 80 of saidhandle is an arm 81 having a lug 82 bearing against the fuel controllever 83. As the control handle 79 is moved in a counterclockwisedirection to the full line position the fuel han-- dle 83 will belikewise moved, but when the handle is moved back to the running ositionthe fuel handle will remain in the ull line position. Connected to thefuel handle by a link 84 is a switch 85 in circuit with a solenoid 86. Alever 87 is also connected to link 84 to actuate a second switch 88 incircuit with rheostat 78. As the fuel handle is thrown to the positionshown it will be seen that both switches are closed. The closing ofswitch 88 willcause the excitation of the fields of generator 74 to agreater or less degree depending upon the position of the arm 70. Saidcoil is composed of material having a high temperature resistancecoeflicient such as nickel or a nickel alloy. Since the battery 92 has aconstant E. M. F. it will be seen that the strength of the solenoid willvary in accordance with the resistance of coil 93 and hence inaccordance with the temperature thereof. The temperature of the coil 93,moreover, de ends directly upon the temperature within t e high pressurecylinder so that the hotter the coil becomes, by reason of the heatwithin the cylinder, the less current flows through the solenoid andhence the greater the resistance interposed by rheostat 78. This weakensthe fields of generator 7 4 and hence lessens the current supplied tocoils 6, 6. Thus, when the engine is starting or at other times when theinterior of the combustion cylinders are not sufliciently hot to insureproper combustion, a large amount of heat will be supplied through coils6, 6 upon which the injected fuel will impinge, but as the heat of thecylinders increases, the introduced heat will decrease in proportion tothe decreasing necessity therefor.

In the construction of the engine, the top member 95 which embraces thetops or heads of all of the cylinders including the domeshapcdclearances 7 of the high pressure cylinders and the flat clearance 3 ofthe low pressure 0 linder is provided with downwardly exten ing skirtsor hollow cylinders 96, 96, 97, which form the upper portions of thehigh and low pressure cylinders. By this means the joints 98 between thetop member 95 and the lower portion 99 of the cylinders which arenecessarily without water jackets are removed from the hottest portionof the cylinder to a much cooler portion, i. e. near the bottom of thecylinder. The water jacketing of the cylinders is also greatlysimplified thereby. It will be seen by this construction that .thecylinders are suspended from the top member 95. Said are effected. Forthis purpose the outer end ofcylinder 3 is closed by a hollow ring 104in which the inlet and outlet valves 105, 106 are contained; the airbeing discharged by way of said outlet valve into said tank 48. Itshould be observed that the effective displacement of'the pump piston103 is somewhat less than that of the low pressure piston 3'-'due to thelarge downwardly extending trunk 103 surrounding the piston rod 150' ofthe low pressure piston and slidably mounted in the guide 151. Theeffective dis- 1 placement of said piston is also substantially greaterthan that of either one of the high pressure pistons 1' or 2 and in factsubstantially reater than, i. e. preferably more than doub e, thecombined displacement of the said pistons. In the engine illustrated therelative displacements of the pistons are approximately as follows,taking the displacement of each high pressure piston at unitDisplacement of the high pressure pistons, each, 1. Combineddisplacement, 2. This displacement, of course, applies both to thesecond compression stage and the first expansion stage as both of thesesta es take place within the same cylinder an on the same side of thepiston.

Displacement of the low pressure piston (second expansion stage), 6.

Displacement of the pump piston-(first compression stage), 5.

In order to regulate the amount or pressure of air delivered to thecylinders, the pressure maintained in tank 48 ma be varied, which inturn may be accomplished by varying the clearance in the compressor endof cylinder .3. For this purpose I may employ a piston 107 working in acylindrical chamber 108 openin into the outer or compressor end of cyliner 3. During the down stroke. of piston 3', compressing air' anddischarging the same into tank 48 through pipe 109 a part of the airwill be compressed into chamber 108. On the upstroke of piston 3 whenvalve 106 closes the air compressed in chamber108 will expand intocylinder 3 and thus limit the amount of air sucked into the compressor.Obviously, by

- decreasing the amount of airdrawn into the compressor,-the amount ofcompressed air delivered is also decreased. Said piston 107 is providedwith a stem 110 passing through bevel gear 111 and threaded thereto. Asecond bevel gear 112 meshes with gear 111 and is provided withactuating means such as a second tube 137 leads.

handle 113 on its shaft 114. The turning of handle 113 will cause stem110 to screw down or up through bevel gear 111 and adjust the piston107. B providing an electric motor 115 havin a evel gear 116 meshingwith gear 112 t e position of iston 107 may be readil controlled throngsuch means.

In ig. 6 I have shown a modified form of the invention in which the fuelvalve is combined in the same unitar structure with the air-inlet andtransfer va ves.

In this form the valveunit 4' is shown in the top central part ofthedome of the high pressure cylinder 1' and having its axis colncidentwith that of said cylinder and may be secured by bolts 129. The transfervalve is shown at 120, the air-inlet valve at 121 within the transfervalve and the fuel valve 122 within the inlet valve (see Fig. 7

The com ressed air char e is brou t in through opening 123, and as inthe previous forms, the various surfaces (1, b, c, and d are soproportioned that the upward pressure of this air upon the valvepredominates and holds the transfer valve normally closed. Similarly thedownward pressure on the surfate e of valve 121 is overcome by theupward pressure against flange 124 secured adjacent the top of the stem125 of said valve by nuts 126, so that the inlet valve is normally heldclosed. The sliding engagement between the flange 124 and the upper partof the transfer valve at 131 is, of course, airtight as is also the enagement between said transfer valve.

rovided on valve 121 and the lower part of the stem 125 thereof, which,being swept by the incoming air which also sweeps over the valve 1' headitself, will cool the head of the inlet valve. Some of these coolingfins, as for instance 127', may extend .hi h enough to engage the innersurface of t e transfer valve as at 128 to act as a guide for the inletvalve. The transfer valve 120 will be cooled by the wash of the air overall of its interior surface. In this connection, the lower part of thisvalve within the space containing the air may be provided with coolingfins 130 for more intensely cooling the lower'part of the valve whichis, of course, the part subjected to the most heat. Guides 134 may beprovided on the transfer valve engaging casing 39 In Fig. 7 theair-inlet valve is shown in section to display the fuel valve. Thehollow stem 1250f the air valveis shown as comprising part of theconduit through which the fuel is carried to the cylinder. 'The fuel is'in turn led into this stem by means of a fiexi-' ble tube 135. This tubeis secured at one end .in a terminal 136 secured to the piston-likeflange 124 (Figs. 6 and 11), into which a The fuel valve 122 is seatedon a member 138 located in the lower part of stem 125 and held in placeby a threaded member 139 (see also Fig. 10) The said member 139 isprovided with an opening 140 for the fuel to pass through; the openingbeing smaller if desired at its lower end as spray which is more or lessaxially projected by reason of said small opening and which isintercepted by the coil 6 with the results hereinbefore pointed out.Among the ad vantages of this type of structure are that in addition tocooling the valves by the incoming air, the air-inlet valve is furthercooled by the incoming fuel. In both instances, 1nstead of dissipatingthe heat absorbed by the valves, it is transferred to the incomingelements of combustion and utilized, and is a conservation of so muchenergy. In order to aid the transfer of heat from the valve to the oiland to assist in setting member 138, guide columns 145 may be providedon member 138 reaching up into stem 125 andresting against wallsthereof. I may also provide guide members 146 (Figs. 7 and 8), betweensaid vanes 145 at the base thereof forming a beveled segmental ring toguide the oil directly through the valve opening. The stem 147 of thefuel valve reaches up through hollow stem 125, passing slidably throughmember 148 and having a sufficiently close fit therewith to preventleakage of oil. Member 148 in turn rests against the inner wall of.stem125 with packing 149 and held in place by member 150 screwed into saidhollow stem.

The following means are provided for actuating the valves: Flanges 151,152 are provided on the upper part of the transfer valve 120, betweenwhich flanges the bifurcated ends 153 of lever 154 engage. Said lever ispivoted at 155 to a bracket 156 secured to the top of the engine. *Theouter end 157 of lever 154 is provided with aroller similar to roller158 and hidden thereby which is adapted to be engaged by a cam 159 oncam shaft 31'. The piston-like flange member 124 on the upper end of theair-inlet stem 125 is provided with a smaller upper flange 160 and isengaged by the bifurcated end 161 of a lever 162 having a roller 158engaging cam 163. Said lever is pivotedto alink 164 which is in turnconnected to lever 154, so that when cam 163 raises lever 162 to openvalve 121 an upward force will be applied to valve 120 through link 164and lever 154.

The top of stem 147 of the fuel valve is provided with flanges 165, 166between which the bifurcated end 167 of a bell crank lever 168 engages.Said lever is pivoted to a bracket 169 projecting upwardly from flanges124, 160 and is connected by a link 170 to a lever 171 pivoted at 172 tobracket 156 and carrying a re ler 178 adapted to be engaged by cam 159to open the valve. A tenslon spring 174 connected at one end to lever168 and at the other to arm 175 reaching out from bracket 169 serves tohold the fuel valve normally closed.

In Fig. 17 I have shown a slight modification in the position of the lowpressure cylinder. In this modification the low pressure cylinder 176 isshown as raised so that the passage 177 leading thereto from the highpressure cylinder will run straight across as shown instead ofdiagonally downward as shown at 177, in Fig. 8. This passage will thusbe made as short and as direct as possible.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle of operation of my invention, together with theapparatus, which I now consider to represent the best embodimentthereof, but I desire to have it understood that, the apparatus shown isonly illustrative and that the invention can be carried out by othermeans. Also, while it is designed to use the Various features andelements in the combination and relations described, some of these maybe altered and others omitted without interfering with the more generalresults outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure byLetters Patent is:

1. In a combustion engine having means for compressing the air supply tothe combustion cylinder, a clearance space of large capacity for saidcylinder, a solid injection fuel feeding device operating during aportion of the expansion stroke within the said combustion cylinder, theaxis of the said solid injection stream being substantially coincidentwith the longitudinal axis of the piston, and induction and eductionvalves leading to said clearance space located at one side of the saidaxis, and tangentially disposed with reference to such axis for inducingvortex action within the cylinder.

2. In a combustion engine having means for compressing the air supply tothe combustion cylinder wherein the compression rises to 400 pounds ormore per square inch, a clearance space for such cylinder with acircular portion having a depth approximating half the piston diameter,a fuel feeding device communicating with such portion of the clearance,and an induction port for said compressed air tangentially arranged withreference to such circular portion for producing a vortex action withinsuch space.

3. In a combustion engine having means for compressing the air supply tothe combustion cylinder wherein the compression rises to 400 pounds ormore per s uare inch, a clearance space for such 0 lin er with acircular portion havin a depth approximately half the piston lamete'r, afuel feeding device communicating with such portion of the clearance,and a combined induction and eduction valve tangentially arranged withreference to such circular portion for producing a vortex action withinsuch space.

i. In a multiple expansion gas engine, the

combination with a high and a low pressure cylinder, of a transfer valvetherebetween, an exhaust valve for the low pressure cylinder, means foroperating each valve, said valves being so timed that the exhaust valvecloses prior to the opening of the transfer valve and before the lowpressure piston completes its return stroke.

5. In a multiple expansion internal com bustion engine, the combinationwith a pair of high pressure cylinders and a common low pressurecylinder, and transfer valves, of means for bringing the pressure andtemperature in the latter cylinder up to approximately the pressure andtemperature of the transfer gases before or at the time the respectivetransfer valve is opened.

6. In a multiple expansion internal combustion engine, the combinationwith the high and low pressure cylinders, transfer and exhaust valvestherefor, of means for closing the exhaust valve of the low pressurepiston on the return stroke thereof and prior to the opening of therespective transfer valve whereby the pressures are equalized.

7. In a vertical compound internal combustion engine a cylinder head orcap constituting a unitary structure containing three cylinder headsconsisting of two high pressure and one low pressure, the said capproviding two dome or hemispherical clearance spaces for the highpressure cylinders, each communicating with the central or low pressurecylinder and means for suspending said cap from adjacent the topthereof.

8. In a vertical compound internal combustion engine a cylinder head orcap constituting a unitary structure containing three cylinderheadsconsisting of two high pressure and one low pressure, the said capproviding two dome or hemispherical clearance spaces for the hi hpressure and a. flat top clearance space for t e low pressure cylinderand means for suspending said cap from adjacent the top thereof.

9. In a vertical compound internal combustion engine a cylinder head orcap constituting a unitary structure containing three cylinder headsconsisting of two high pressure and one low pressure, each head having askirt projection extending downwardly, so as to provide in part wallsfor said cylinders, means for suspending said cap from adjacent the topthereof and a detachable lower portion secured to said skirt whereby thepiston 10. In a vertical compound internal combustion engine, a unitarycap plate, including cylinder heads for each cylinder and a portion ofthe walls of each cylinder, water jackets therefor, a lower portion alsohaving a water jacket of each cylinder detachably securedto said cap,the joints between said portions and the caps being situated below thehottest'portions of the cylinders but above or in line with the top ofthe piston when in its lowermost position and means for suspending saidcap from adjacent the top thereo 11. In an internal combustion engine,the combination with the cylinder, of inwardly opening combined intakeand exhaust valves,

a source of compressed air for the intake and a piston on each valvesubject to the pressure of said air for holding each valve outwardlyagainst its seat.

\ 12. In a multiple expansion internal .combustion engine,the'combination with a high and a low pressure cylinder, of an inwardlyopening hollow transfer valve located in the clearance of the formercylinder, and an inwardly opening intake valve therefor having a hollowstem mounted and seated within said transfer valve whereby the intakeair flows around and down the said stem, the last named valve beingadapted to contain a volatile liquid whereby the heat of the end of thevalve is transferred to the air cooled stem.

13. In an internal combustion engine in which the intake air isprecompressed, a high pressure cylinder, a low pressure cylinder, a

transfer valve for transferring the partly expanded heated gases fromthe high pressure to the low pressure cylinder, two pistons thereon, oneof which is the larger, and an inlet for said air between the pistons tohold said valve on its seat.

14. In an internal combustion engine in which the intake air isprecompressed, a high pressure cylinder, a low pressure cylinder, atransfer valve for transferring the partly expanded heated gases fromthe high pressure to the low pressure cylinder, two pistons thereon,means for introducing said air between said pistons and for causing acirculation thereof in contact with said valve whereby said valve isboth cooled and held on its seat thereby.

15. In an internal combustion engine in which the intake air isprecompressed, a high pressure cylinder, a lowpressure c linder, atransfer valve for transferrin the partly expanded heated gases from thehigh pressure to the-low pressure cylinder, two pistons thereon, meansfor introducing said air between said pistons,and a concentricallymounted intake valve within said transfer valve in communication withair.

16. In a multiple expansion engine in which the intake air isprecompressed, a transfer valve, a valve seat therefor, an intake valveseated thereon, a piston on said intake Valve subject to the pressure ofthe intake air for holding both the valves on their seats, and a pistonon said transfer valve subject to said pressure for holding the same onits seat When the intake valve is opened.

17. In a multiple expansion engine in Which the intake air isprecompressed, a transfer valve, an intake valve, one of said valvesbeing seated on the other, a piston on the valve which is seated on theother valve for holding both valves on their seats, and a piston on the,other of said valves for holding it on its seat when the first namedvalve is opened.

18. In a combustion engine having means for compressing the air supplyto the combustion cylinder, the combination with a combustion cylinderwherein the compression rises to 400 pounds or more per square inch, aclearance space for such cylinder having a depth approximating half thediameter, an expansion cylinder, a transfer valve between saidcylinders, an exhaust valve for the expansion cylinder, and means forclosing the latter before its piston reaches the end of its strokewhereby the pressure in the two cylinders is rendered substantiallyequal at the time the transfer valve is opened.

19. In a multiple expansion internal combustion engine, the combinationwith the high and low pressure cylinders, transfer and exhaust valvestherefor, the low pressure cylin der having a remote passage or chamberconneeted with the clearance space thereof, of means for closing theexhaust valve on the return stroke of the low pressure piston and priorto the opening of the transfer valve whereby the pressures areequalized.

20. In a combustion engine having means for compressing the air supplyto the combustion cylinder, the combination with a combustion cylinderwherein the compression rises to 400 pounds or more per uare inch, aclearance space for such cylin er having a depth a proximating half thediameter, an expansion cylinder of at least four times the capacto thepressure of the entering gases at the time said valve is opened.

22. In a heat engine, the combination with a working cylinder forexpanding the hot gases, of an intake valve therefor, means for coolingthe same by circulation thereover of,

cooler fluid after each passage of the hot intake gases, and means forbringing the pressure within said cylinder substantially up to thepressure of the entering gases at the time said valve is opened.

23. In a heat engine, the combination with a combustion s 'ace where hotproducts of combustion are developed, of a separate cylinder forexpanding the hot gases, an intake valve therefor, fluid means forcooling the same, and means for bringingthe pressure within saidcylinder substantially up to the pressure of the entering gases at thetime said valve is opened.

24. In a heat engine, the combination with a combustion space where hotproducts of combination are developed, of a separate cylinder forexpanding the hot gases, a combined intake valve for said combustionspace and intake valve for said expandin cylinder where by said valve iskept cool by the incoming ases to said combustion space, and means forringing the pressure within said cylinder substantially up to thepressure of the enterin" gases at the time the first named intake 'vaIveis opened.

In testimony whereof I have aflixed my signature.

ELMER A. SPERRY.

